Contrast their percentages with that of Mantle who led in OPS. Mantle probably benefited from having significantly fewer opportunities.

Below are the top 25 batters with the biggest positive difference in OPS:For entire career, Ext inning (within By Inning), (requiring PA≥100 and onbase_plus_slugging≥0), sorted by greatest difference between On-Base Plus Slugging for this split and the overall total

Jack Clark has significantly more PA than most in this group: 232; Will Clark is second with 186. Fewer PA, better to have high OPS. Jerry Lumpe (52.86%) has both the biggest point difference and also the biggest percent difference between OPS in extra innings and for career using career as the base. Horace Clarke (50.80%) is the only other with 50% for better over career OPS. Mantle was 34.60% above, which is remarkable considering his very high career OPS: .977, 11th best all time.

19 batters hit at least ten home runs in extra innings. Here they are with their extra inning home rate, i.e, home runs per at bat: